(a) Technical Field
The present disclosure relates to a method for controlling two arms of a robot that can easily make the two arms level when controlling a wearable robot with the two arms lifting a weight.
(b) Background Art
Wearable muscle force assistive robots are provided for a wearer to lift or move objects while wearing the robot in industrial fields.
When lifting a weight with two arms in accordance with an intention of a wearer, a muscle force assistive wearable robot can help lift the weight because a force is transmitted from the wearer to the robot and the transmitted force is amplified through the robot.
The present disclosure relates to an algorithm for controlling a muscle force assistive wearable robot such that upper arms simultaneously and stably move when lifting a weight. The present disclosure is very useful particularly when lifting an object that is relatively heavy, such that horizontality needs to be maintained.
When existing muscle force assistive wearable robots lift a heavy weight with two arms, the arms simultaneously move by reflecting an intention of a wearer to the arms, respectively.
When lifting a heavy weight with two arms of the robot while keeping the arms level, a wearer has to keep the arms level by separately moving the arms, so that the wearer feels a large amount of fatigue.
Further, the balance of the robots may be rapidly broken, when a heavy weight is inclined to a side. The present disclosure enables synchronizing two arms even in this case such that the heavy weight does not incline to a side, and can therefore be considered as being very useful in the industrial fields.
KR10-2008-0079590 A in the related art has proposed a “friction compensation method, a friction compensator, and a motor control device” in which an actual locator 21 estimates the actual position of a moving object in response to a location signal and generates an actual position signal, a differentiator 22 finds a velocity signal by differentiating the actual position signal, an integrator 24 generates a displacement signal at a position where the moving object changes the movement direction by integrating the velocity signal, an absolute value calculator 25 finds the absolute value, a frictional property estimator 26 finds a rate of change of a friction force or friction torque to the displacement, a multiplier 27 finds a rate of change to time by multiplying the rate of change to the displacement by the velocity signal, and an integrator 28 estimates the friction force or the friction torque by integrating the rate of change to time.
However, there has not been proposed a way of synchronizing two arms lifting a heavy weight, so that a control method that can control even this situation is required in the art.
The description provided above as related art of the present disclosure is just for helping understand the background of the present disclosure and should not be construed as being included in the related art known by those skilled in the art.
(Patent Document 1) KR-10-2008-0079590 A